Water-bombing aircraft and 25 firefighters are attending an out-of-control bushfire on the western edge of the Blue Mountains National Park.
Residents on Shipley Road in Blackheath have been told to monitor the conditions and follow their bushfire survival plan.
The fire is burning between Mt Blackheath Road and Kanimbla Drive and moving in an easterly direction.
A NSW Fire Service spokesperson said: "Under these conditions, fires can be difficult to control".
"Embers may be blown ahead of the fire, creating spot fires," he said.
"These spot fires may threaten your home earlier than the predicted main fire front."